National Geographic : 1936 Apr
Photograph byMyra Keen WITH TINY MUD PELLETS, CARRIED ONE AT A TIME, CLIFF SWALLOWS BUILT THESE COZY, JUG-SHAPED NESTS Some of the occupants are peeking out of their homes. The small white spot visible in the lower of two adjacent openings near thetopcenter ofthepicture is the marking on a bird's forehead. Clever architects, cliff swallows make the entrances only large enough to admit the owners, and point theholes downward tokeep out rain. This colony has utilized a shallow cave made by an overhanging rock near Colorado Springs. In the easternpart ofNorth America, thebirds often settle under the eaves of a building, a habit which earns for them the name eave swallows (see Color Plate VI, and text, page 542).